Police declined to release any information about the incident, other than it was a "possible mental illness situation."
"There was no threat, no weapon — just odd behavior in the bank," said Lt. Mark Bennett of the Ottawa County Sheriff's Department.
Sheriff's deputies and Grand Haven public safety officers were called to the bank shortly before 11 a.m. about a "suspicious" man outside it.
The man was taken into police custody.
Macatawa Bank was open Monday, despite it being the Columbus Day holiday.